ABB Industrial IT enabled REX 521 Technical Reference Manual, General page 28

5(; 
28
3URWHFWLRQ 5HOD\
Technical Reference Manual, General
COM-port (RS 232)
SPA-bus
SPA-ZC22
R E X 5 2x
R E X 5 2x
REX 521 REX 521
)LJ  ([DPSOH RI D 63$EDVHG VXEVWDWLRQ DXWRPDWLRQ V\VWHP
In the case of longer transmission distance, for example between MicroSCADA
system and a substation, the system configuration presented in the following figure
(Fig. 4.1.12.5.-2) is recommended.
MicroSCADA
Optical SPA-bus
SPA-ZC21 RER 103
SPAC 331 C
I
O
SPACOM
1MRS 751108-MUM
COM-port (RS 232)
Protocol X
I
0
F
C
E
REF 54_
spasysrex_a